Yes, Fred was born in 1888 not 1889. I'll correct that now...don't know how I got a year out.
Unfortunately I don't know where Dinky and Percy were born. As I said Fred was in Southwell in 1911 but he could easily have moved away. Some of his siblings went to Nottingham, some to Beeston. His oldest brother Walter moved to London and his sister Lois lived in Selston, Notts. So when he married, he could have gone anywhere. Just looking at FreeBMD now it doesn't seem that he stayed within the Southwell district. I also searched for deaths of Peggy Hall (and Margaret, any other variants?) age 31 with no results.
I did begin a search of the death index for Fred and his brothers which quickly turned to failure. Though I didn't search many years at all, there was one possible entry for Fred Hall, died Dec 1948, age 59, Eastbourne. Pretty sure it's not the right one though.
I don't know if it's possible to progress further without more information.
Alexander